The present invention relates to a novel voice or speech prothesis device of the type which is inserted into a surgically created opening communicating the trachea and esophagus of a laryngectomized patient. Specifically, the invention relates particularly to the manner in which the membrane-like, tabbed flap or disc of a one-way flap-type valve is positioned within the tubular housing of the prosthetic device. The seating and superiorily hinged positioning of the flap of the check-valve provides that a significant degree of decreased resistance to airflow is obtained when the voice prosthesis device is constructed and formed in accordance with the teachings of the present invention.
Voice prostheses devices are known which may be inserted into a surgically created fistula between the trachea and esophagus of a laryngectomized patient and it is known that it is desirable for such devices to offer low resistance to air flow. Examples of voice prothesis devices embodying a flap-type check-valve are described in U.S. Pat. Nos. 4,435,853 and 4,610,691.
In particular, the U.S. Pat. No. 4,610,691 discloses that by selecting a particular modulus and hardness for the membrane-like flap or disc of the one-way check valves used in a voice prosthesis device, and by attaching or anchoring the periphery of each flap or disc adjacent to the prosthesis housing, voice prosthesis devices may be produced in commercial quantities, with a pre-determined uniform resistance to airflow which may be equal to, less than or greater than the resistance offered by the normal human larynx. However, when the modulus and hardness of the membrane-like flap or disc of the one way check-valve is selected to accomplish a resistance to air flow that is substantially less than that offered by the normal human larynx, the flap or disc may, on occasion, herniate through the seat valve. When the flap or disc does herniate beyond the valve seat, esophageal contents may enter the trachea and speech is impaired until or unless the herniated flap is returned to its correct position by air flow from the trachea through the device.
One object of the present invention is to provide a novel voice or speech prosthesis device having a one-way check-valve whose membrane-like, tabbed flap or disc is of sufficient modulus and hardness to prevent and substantially eliminate the occurrence of flap herniation beyond the valve seat while at the same time offering a resistance to airflow which is substantially below that offered by the normal human larynx.
Another object of the present invention is a novel prosthesis device having a one-way check-valve wherein its membrane-like, tabbed flap or disc is seated at an angle which is oblique in reference to the longitudinal axis of the tubular housing and which is superiorily hinged thereto to provide a speech prosthesis device possessing substantially less resistance to airflow than the resistance to airflow offered by the normal human larynx.
Still another object of the present invention is a novel voice or speech prosthesis device having a membrane-like, tabbed flap or disc seated within the tubular housing at an angle which is oblique in reference to the longitudinal axis of the tubular housing to provide a prosthesis device having a substantially decreased resistance to airflow as compared to that of a normal human larynx without resorting to altering the modulus and hardness of the material of the tabbed flap or disc to a point which invites herniation of the flap through its valve seat.
Still a further object of the present invention is a novel voice or speech prothesis device wherein the tubular housing may include a bullet or dome-shaped distal end which does not compromise the devices resistance to airflow through and which facilitates insertion of the speech prothesis device through the surgically created fistula.
For a more complete understanding of the scope and nature of the present invention, reference may now be had to the accompanying drawings and the following detailed description of the presently preferred embodiments of the present invention.